Rack support system



Get 1 1957 J. E. BEBINGER 3,347,612

RACK SUPPORT SYSTEM Filed Feb. 14, 1966 IN VENTOR.

Jack EBebinger BYW W Attorney United States Patent Ofiice 3,3415 i2 Patented Oct. 17, 1967 3,347,612 RACK SUPPGRT SYSTEM Jack E. Bebinger, Brookfield, Wis, assignor to General Electric Company, a corporation of New York Filed Feb. 14, I966, Ser. No. 527,232 6 Claims. (CL 312311) ABSTRA CT 6F THE DISELGSURE A rack support system having rollers with rolling surfaces of different diameters. The surface of smaller diameter is adapted to roll upon a track within a dishwasher wash chamber while the surface of larger diameter is adapted to roll upon a track on the opened door as the rack is withdrawn from the wash chamber. The door track is positioned below the chamber track when the door is in its open position.

This invention relates to a support system for racks, and more particularly to a rack support system which is designed for use in a cabinet structure having a bottom hinged front door which supports the rack in a horizontal position as it is withdrawn from the interior of the cabinet.

Although my invention is applicable broadly to racks which may be used in cabinets of all types wherein an extended rack is supported on an open front door, it has proven to be very advantageous in domestic dishwashers of the front-opening type. A principal feature of my invention is that the means for supporting the rack within the cabinet is located above the plane of the door when the door is in the horizontal open position, and yet the rack is maintained in the same horizontal plane while supported in either the cabinet interior or on the open door.

It is a principal object of my invention to provide a rack support system capable of maintaining a rack in a straight, continuous, horizontal path as the rack moves between two supporting surfaces of different elevations.

Another object of my invention is to provide a rack support system for a dishwasher rack which results in a substantial cost reduction over more conventional structure of a' like nature by eliminating many of the parts heretofore required to achieve the same function.

In one aspect of my invention, I provide a chamber having side walls and a front door pivotable about its bottom edge between a vertical closed position and. a horizontal open position. Within the chamber is an article support rack disposed for movement in a continuous horizontal path between the interior of the chamber and a position partly outside the chamber wherein the front end of the rack is supported on the open door. Inside the chamber, and on opposite side walls thereof, are disposed a pair of support means which are positioned above and parallzl to the door when the door is in the horizontal ope-n position, the support means and the door thereby providing support surfaces of different elevations for the rack. Secured to each opposite side of the track and parallel to the side walls of the chamber, are front and rear wheels, each ofwhich has a first rolling surface thereon to support the rack on the aforementioned support means when the rack is within the wash chamber. The front wheel means have a second rolling surface thereon co-aXial with the first; the second rolling surface supports the rack on the door when the rack is partially withdrawn from the chamber. The radius of the second rolling surface exceeds the radius of the first rolling surface by a length substantially equal to the difference in elevation between the support means and the door, whereby when the rack is in the partially extended position the second rolling surface of the front wheel means supports the front of the rack on the door, while the first rolling surface of the rear wheel means support the rear of said rack on the support means in the chamber, with the rack being supported in a substantially horizontal plane.

Other features and advantages of my invention will be apparent from the following detailed description of a presently preferred embodiment thereof, read in connection with the accompanying drawings in which:

FIGURE 1 is a side elevational view in partial cross section of a dishwasher embodying my improved rack support wheel;

FIGURE 2 is an enlarged fragmentary front view taken along the line 22 of FIGURE 1, illustrating my rack support wheel when the rack is in the extended position on the open door; and,

FIGURE 3 is an enlarged fragmentary view taken along the line 3-3 of FIGURE 1, and shows the rack and wheel as supported on its second rolling surface within the wash chamber.

Referring first to FIGURE 1, there is shown a dishwashing machine 1; in this case the dishwasher is specifically of the built-in type, although my invention is also applicable to dishwashers or other cabinets of the front-opening type. Dishwasher 1 has an enclosure or tub 2 formed with sides including a back wall 3, side walls 4, a bottom wall or section 5, and a top wall 6. The tub and outer structure are constructed to provide registering front wall openings, with respect to which a door 7 is hinged at its bottom (hinges not shown) so as to swing between the normally closed substantially vertical position shown in the dashed lines of FIGURE 1, and the substantially horizontal open position shown in the full lines of FIGURE 1. Suitable gasket means (not shown) are normally interposed between the door and the periphery of the tub opening to provide for sealing against the leakage of water during operation of the machine.

A pair of vertically spaced racks 8 and 9 are provided within tub 2. Each of the two racks is formed of wire in a conventional manner so as to receive, in suitable position for washing, a varied asosrtment of dishes, glassware and the like (not shown). Also, each of the two racks is mounted so as to move horizontally forward (to the left, as viewed in FIGURE 1) when door 7 is opened, so that the articles in the racks are accessible for loading and unloading purposes. The support system for giving the desired movability to upper rack 8 may be of any conventional design, the structure herein illustrated being identical to that disclosed by Fitzpatrick and Krzewina, in US. Patent No. 3,288,302, for Support System and assigned to the General Electric Company, assignee of the present invention. The support arrangement for giving the desired movability to the lower rack 9, including the two-level rack support system of my invention, will be discussed in detail herebelow, after the general description of the dishwasher is completed.

A conventional time-cycle control 10 is mounted in a convenient location in the upper portion of door 7. By well known circuitry, control 10 is arranged to control the operating mechanism disposed in a machinery compartment 11 below the tub, programming the mechanism so as to provide a desired sequence of washing and rinsing operations, and a final drying operation. The mechanism within compartment 11 may include, for instance, a solenoid valve 12 connected by piping 13 to a hot water supply (not shown) and supplying water inlet fitting 15 so as to provide the one inch air-gap generally required by plumbing codes.

The operating components may further include a pump 16 arranged to be driven by a reversible electric motor 17 and providing for the recirculation of water from the sump portion 18 of the tub through a cylindrical pump discharge outlet 19. The recirculation system will normally include a peripheral inlet to the pump, the inlet being provided with any suitable screening or filter device such as that shown at 20. Pump 16 is usually of the axial flow type, having a shroud or cover 21 which directs the pump discharge to a vertical flow throughoutlet 19.

The pump structure of the. dishwasher shown also includes in its lower portion a secondary pump chamber 22 containing a bladed rotor (not shown) which is effective to pump a substantial amount of liquid when rotating in one direction, but has substantially no pumping action when rotated in the opposite direction. The pump casing surrounding the secondary pump chamber communicates with a discharge conduit 23 which carries the vitiated fluids from the dishwasher to any suitable sewer or septic line (not shown) when the pump is rotating in the appropriate direction.

Outlet 19 communicates with a reaction type spray arm 24 having orifices 24A arranged in the usual way so, that, upon issuance of water therefrom, spray arm 24 is caused to rotate, the water upon issuance providing a cleaning effect on the dishes contained in racks 8 and 9. In addition to the spray arm. 24, the dishwasher may include a conduit 25 leading from the spray arm up to another water discharge device, such as that shown at 26, which is particularly suited to discharge liquid between racks 8 and 9. This has the effect of improving the washing of articles in rack 8 and rinsing down any food particles which may be on the articles in rack 9. It will be understood that member 26 may either be rotated by mechanical connection to spray arm 24 through conduit 25, or by having jet orifices of its own to provide the reaction force necessary for rotation.

It is desirable in machines of this type that the lower rack 9 be mounted so that it will move horizontally to a position at least partly outside the tub when door 7 is opened, as shown in FIGURE 1. conventionally, this movement has been accomplished by providing the lower rack with a series of wheels that rolled within track structures (not shown) which were secured to the side walls of the tub, and then, as the rack moved horizontally out of the tub, the wheels continued to roll on appropriately formed surfaces provided on the inner face. of the door, which as has been stated, is substantially horizontal when open. An example of this structure is illustrated in FIGURE 1 of Zurek Patent No. 3,009,470, issued Nov. 21, 1961,. and assigned to the General Electric Company, assignee of the present invention. It is to this roller and track arrangement that my present invention is specifically directed.

Turning now to FIGURES 2 and 3 wherein my invention is best illustrated, it will be observed that wheel 28 comprises two co-axial rolling surfaces of different diameters disposed along a single shaft. The smaller diameter rolling surface .29 is adapted to ride freely on the embossment 27 formed on side wall 4 while rack 9 is within wash chamber 2. When rack 9 is withdrawn from wash chamber 2 for loading and unloading, the larger diameter rolling surface 30 rolls on the track 31 provided along the inner panel 32 of door 7. The larger diameter surface, of course, permits the rack to roll more easily along the door track than would be the case if a smaller diameter wheel were provided. The two rolling surfaces, 29 and 30, may be made an integrated part as shown, or two separate wheels of different diameters may be provided along a single shaft. .In the embodiment shown, shaft 33 is secured to rack 9 by means of an extension 34 of the wire forming the bottom of the rack structure.

The relative sizing of the two rolling surfaces is deembossment 27. The radius of the smaller rolling surface 29 is equal to the distance of the center of shaft 33 v to the top of embossment 27. The radius of thesecond rolling surface 30 exceeds that of the first rolling surface 29 by a length equivalentto the distance between track 31 on door 7 and the top of embossment 27 .When the height of embossment 27 is fixed and wheel 28 constructed in accordance with the require-d dimensions, it is apparent that rack 9 will be supported in the same horizontal plane while supported on either rolling surface 29 and embossment 27, or by rolling surface 30 and track 31, and during the transition therebetween, notwithstanding that the respective supporting surfaces 27 and 31 are at two different elevations.

The smaller diameter rolling surface 29 is preferably tapered as it extends outwardly from the point adjacent the larger diameter rolling surface 30, to its termination point. The tapering of the smaller, diameter rolling surface allows the wheel, and of course, the rack, to make a smooth transition between the two support levels when rolling surface 29 contacts embossment 27 as the rack is returned to the wash chamber.

When the rack is fully loaded, the weight distribution.

thereon may tend to bow shaft 33 upwardly, with the possibility that the segment of the wheel then above the shaft could bind against the rack. It is desirable, therefore, to cant the shaft 33 approximately 4 below the horizontal with respect to rack 9, to counteract the downward forces on the rack and insure that the wheel cannot jam against the rack when the rack is loaded. Because the smaller diameter surface of the wheel is tapered, canting of the shaft in the aforementioned manner will not adversely affect the ability of the wheel to roll on embossment 27, as the tapered rolling surface will accommodate deviations of the wheel from a true vertical plane.

A dishwasher constructed in accorlance with my invention allows the manufacturer limited flexibility, in that the height of the embossment relative to the tub bottom may be varied within certain limitations to permit the inclusion of other elements, such as an airivent, along the side wall at a point where it could not be so disposed when the tracks were secured thereto and the wheels were of the conventional structure. The variance in. height of the support structure within the chamber is accommodated by merely changing the diameter of rolling surface 29 accordingly.

While I have shown the details of only one side of the rack and wash chamber, it should be understood that identical structure is needed to support they opposite side of the track. In addition, in those cabinets wherein it is not desirable to fully withdraw the rack from the chamber, only the two front wheels on the opposite sides of the rack need be constructed in accordance with my invention, the rear wheels may be of a single diameter since they will remain on the supporting surfaces within the chamber.

While there has been described what is at present thoughtto be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit, and scope of the invention.

1 claim:

1. In a structure providing a chamber having side walls and a front door pivotable about its bottom edge between a substantially vertical closed position and a substantially horizontal open position, and having an article (a) a pair of parallel support means within said cham ber disposed on said side walls in a position above and substantially parallel to said door when said door is in said open position, said support means and said door providing two support surfaces of different elevations for said rack;

(b) front and rear wheel means secured to each opposite side of said rack parallel to said side walls;

(c) each of said wheel means having a first rolling surface thereon for supporting said rack on said support means when said rack is within said chamber;

(d) said front wheel means having a second rolling surface thereon co-axial with said first rolling surface for supporting said rack on said door, the radius of said second rolling surface exceeding the radius of said first rolling surface by a length substantially equal to the difference in elevation between said support means and said door, whereby when said rack is in the partially extended position said second rolling surface of said front wheel means supports the front of said rack on said door while said first rolling surface of said rear wheel means supports the rear of said rack on said support means in said chamber, with said rack being supported in a substantially horizontal plane.

2. The combination according to claim 1 wherein said rack is adapted to extend completely out of said chamber and wherein said rear wheel means include said second rolling surface, whereby when said rack is in the fully extended position said second rolling surface of said front and rear wheel means maintains said rack in substantially the same horizontal plane while supported by said door as does said first rolling surfaces while supporting said rack on said higher support means Within said chamber.

3. The combination according to claim 1 wherein said structure providing said chamber and said door comprises a dishwasher of the front-opening type; said support means on said side walls comprise inwardly extending embossments formed as integral members of said side walls, and said first rolling surface of said wheel means is disposed for rolling movement upon said embossments when said rack is within said chamber.

4, The combination according to claim 1 further ineluding a pair of parallel track means disposed on the support side of said door, said track means being substantially parallel to and below said support means when said door is in the open position, said track means being spaced inwardly with respect to said support means and out of alignment therewith; said second rolling surface of said wheel means being disposed immediately adjacent the sides of said rack and in vertical alignment with said track means; said first rolling surfaces extending outwardly from said second rolling surfaces and in substantial vertical alignment with said support means for rolling engagement therewith when said rack is within said chamber.

5. The combination according to claim 4 wherein said first rolling surface of said wheel means tapers to a smaller rolling surface as it extends outwardly from said second rolling surface to its termination near said side walls, whereby said tapered rolling surface will accommodate a relatively small downward or sideward displacement of said rack during transition of said rack between its extended position on said door and its supported position within said chamber.

6. The combination according to claim 5 wherein said wheel means are secured directly to said opposite sides of said rack by shaft means extending toward said side walls from the bottom of said rack, said shaft means being inclined at a relatively small angle below the horizontal as they extend outwardly from said rack, to thereby aid in aligning said wheels in a vertical plane when said rack is loaded.

References Cited UNITED STATES PATENTS 1,446,784 2/1923 Carter 295-8.5 2,745,707 5/1956 Sebens 312-311 2,821,151 1/1958 Neister et. al. 295- 2,870,904 1/1959 Tar-box 312-311 3,098,685 7/1963 Stiner et a1. 312-311 3,146,045 8/1964 Kauffman 312-311 X 3,195,970 7/1965 Chuboif 312-311 3,248,158 4/1966 Ullman 312-311 DAVID J. WILLIAMOWSKY, Primary Examiner, JAMES T. MCCALL, Examiner, 

1. IN A STRUCTURE PROVIDING A CHAMBER HAVING SIDE WALLS AND A FRONT DOOR PIVOTABLE ABOUT ITS BOTTOM EDGE BETWEEN A SUBSTANTIALLY VERTICAL CLOSED POSITION AND A SUBTANTIALLY HORIZONTAL OPEN POSITION, AND HAVING AN ARTICLE SUPPORT RACK DISPOSED FOR MOVEMENT IN A CONTINOUS HORIZONTAL PATH BETWEEN THE INTERIOR OF SAID CHAMBER AND A POSITION PARTLY OUTSIDE SAID CHAMBER WHEREIN THE FRONT END OF SAID RACK IS SUPPORTED ON SAID DOOR WHEN SAID DOOR IS IN THE HORIZONTAL OPEN POSITION, SUPPORT STRUCTURE FOR SAID RACK COMPRISING: (A) A PAIR OF PARALLEL SUPPORT MEANS WITHIN SAID CHAMBER DISPOSED ON SAID SIDE WALLS IN A POSITION ABOVE AND SUBSTANTIALLY PARALLEL TO SAID DOOR WHEN SAID DOOR IS IN SAID OPEN POSITION, SAID SUPPORT MEANS AND SAID DOOR PROVIDING TWO SUPPORT SURFACES OF DIFFERENT ELEVATIONS FOR SAID RACK; (B) FRONT AND REAR WHEEL MEANS SECURED TO EACH OPPOSITE SIDE OF SAID RACK PARALLEL TO SAID SIDE WALLS; (C) EACH OF SAID WHEEL MEANS HAVING A FIRST ROLLING SURFACE THEREON FOR SUPPORTING SAID RACK ON SAID SUPPORT MEANS WHEN SAID RACK IS WITHIN SAID CHAMBER; (D) SAID FRONT WHEEL MEANS HAVING A SECOND ROLLING SURFACE THEREON CO-AXIAL WITH SAID FIRST ROLLING SURFACE 